Though the 2 1/2-week effort produced few volunteer deportees among illegal immigrants who are under court orders to leave the country, a U.S. Immigration and Customs Enforcement official said his agency will arrest more of them this year than last  and still more next year as more agents are assigned.

"We are going to continue our enforcement of immigration law whether it is convenient for people, or whether it's not convenient," Jim Hayes, ICE's acting director of detention and removal operations, told reporters.

"Congress has mandated that we enforce these laws and that is what we intend to do," he said.

Immigrant advocates accused ICE of using the failure of the "Scheduled Departure" program to justify raids that have caused many illegal immigrants to live in fear of a pre-dawn knock on the door. They ridiculed the self-deportation program, saying it gave people no incentive to surrender.

"It seems to me ICE used this as nothing more than a publicity ploy as a means to justify their harsh enforcement of immigration law," said Charles Kuck, president of the American Immigration Lawyers Association.

Kuck said he supports enforcement but that ICE could handle cases in a gentler way after arresting people at home. Instead of jailing them, for example, they could allow them to wear ankle bracelets while preparing to depart.

The self-deportation pilot program gave illegal immigrants up to 90 days to leave the country and was intended to quell criticism that its enforcement is heavy-handed and disruptive to families. Critics noted that those who participates were barred from returning to the United States for as long as a decade.

The program applied to only about 457,000 of the estimated 12 million illegal immigrants nationwide. It was open only to those who have ignored judicial orders to leave the country but have no criminal record.

The program was offered in five cities: Charlotte, N.C., Chicago, Phoenix, San Diego and Santa Ana. ICE estimates that 30,000 eligible immigrants live in those areas.

ICE has been steadily expanding the number of agents charged with finding fugitive illegal immigrants. Its fugitive operation teams made more than 30,000 arrests during the last fiscal year, nearly double from the previous 12-month period.

Hayes said that during the time the self-deportation program was going on, the teams made 1,300 arrests.

Critics say ICE often arrests others who just happen to be at home when agents come looking for fugitives. About 31 percent of immigrants arrested by the teams last year had no order to leave the country or criminal record.

ICE has also been increasingly raiding workplaces, including nearly 400 people in May at an Iowa meatpacking plant, the largest single-site raid in U.S. history.

The eight volunteers include an Estonian man in Phoenix, a Guatemalan man and Indian couple in Chicago, a Salvadoran man in Charlotte, a Mexican woman in San Diego and a Guatemalan man and Lebanese man in Santa Ana, according to ICE.

ICE spent $41,000 to advertise the program. Hayes said the government saved money because the cost of detaining the eight who turned themselves in would have been $54,000.